Last weeks comments by the Corps of Engeneers that the failure of the 17th Street Canal levee could not have been forseen was dealt a blow when yesterday, researchers studying the failures stated that had test borings been done at he toe of the levees would have identified the weak soils in that location.
Lost in the controversy swirling around a government panel's comment last week that the designers of the floodwall could not have anticipated the combination of forces that brought the structure down was its finding that one of the main triggers for that failure -- extremely low soil strengths under the toe of the levee -- would have been detected had the design team done soil borings in that area, an official with the Army Corps of Engineers said Thursday.
Had the weakness at the toe of the levee been included in the analysis system used by the project designers, "The factor of safety would have been (low enough) to where they would have changed the design," said Reed Mosher, a researcher at the corps' Engineering Research and Development Center in Vicksburg, Miss., and a member of the corps-sponsored Interagency Performance Evaluation Task Force that is investigating the failures. The options considered probably would have included a T-wall, or a much larger levee, he said.
The Corps has repeatedly said through its spokeman that they will accept any determination of the investigation team and report any findings of their own investigation. Neither one of these has taken place. They have engaged in spin, the likes of which would make the Clinton Administration blush, and conducted investigations that amount to little more that a whitewash.
Although the quality of the engineering done by local firms and reviewed by the corps has been the focus of scrutiny since shortly after the walls collapsed, it was pushed from the headlines last week when the task force released an interim report identifying how the walls collapsed and saying the combination of forces responsible could not have been anticipated by the project designers. That provoked criticism from independent investigators.
But this week Ed Link, project director for the task force, said his panel's statements had been misconstrued by the media.
"Our position on this is that, very simply, whoever did the design just did not consider this particular mechanism," said Link, a University of Maryland senior fellow who is head of the corps-sponsored Interagency Performance Evaluation Task Force. "We, IPET, made no value judgment whether it should have been considered or could have been considered.
"If that was inferred by our comments, it was inaccurate."
Furthermore, Reed Mosher, a researcher at the corps' Engineering Research and Development Center in Vicksburg, Miss., and a member of the corps-sponsored Interagency Performance Evaluation Task Force, was one of the authors of the paper that described the failure of a floodwall in a 1986 test conducted by the Corps of Engineers.
"We were looking at the design criteria to see if there was a process like this described in the corps' design manuals that (the design team) missed," he said. "We didn't see anything that described this mechanism, that would have alerted (the design team) to look for this when doing their analysis."
Link and Mosher disagreed with Bea and Seed's analysis of the importance of the 1986 study. Mosher, who analyzed the E-99 report, said it was not designed to look at levee stability, but at how much a sheet pile "moved at the top as water increased."
The fact that the test also showed there was evidence of tension cracking and high pressure at the toe of the wall was not given much attention at the time, Mosher said, "because the study was not designed to look at the stability of the levee." He also said the evidence of cracking and increased pressure was minimal.
So let's see if I get this right. The Corps of Engineers conducts a study to investigate not levee stability but movement of the sheet piles. According to the independent study group, movement of the top of the sheet piles caused instability within the levee. Therefore, the results of the 1986 study should have had no impact on the design of the New Orleans floodwalls.
I guess because the Corps of Engineers are a government organization that it's employees get away with saying that it's not their fault that their work is shoddy.